JQuery: detect change in input field

I want to detect when a user's keyboard actions alter the value of a text field. It should work consistently across modern browsers.

The JQuery page for the .keypress event says it's not consistent? Also, it doesn't work for backspace, delete etc.

I can't use .keydown as it is because it reacts to shift, alt and arrow keys etc. Also, it doesn't fire more than once when the user holds down a key and multiple characters are inserted.

Is there a concise method I'm missing? Or should I use .keydown and filter out events that are triggered by arrow keys, shift and so on? My main concern is there will be keys that I'm not aware should be filtered. (I nearly forgot about alt and ctrl, I suppose there could be others) But then how would I detect the key being held down and inserting multiple characters?

As a bonus it would detect changes due to pasting (including right-clicking) but I have the solution to that from [here][1].

[1]: https://stackoverflow.com/questions/1601353/detect-paste-on-input-box "here"

You can bind the 'input' event to the textbox. This would fire every time the input changes, so when you paste something (even with right click), delete and type anything.

$('#myTextbox').on('input', function() {
    // do something
});

If you use the change handler, this will only fire after the user deselects the input box, which may not be what you want.

There is an example of both here: http://jsfiddle.net/6bSX6/

Use jquery [change event][1]

> Description: Bind an event handler to the "change" JavaScript event, > or trigger that event on an element.

An example

$("input[type='text']").change( function() {
  // your code
});

The advantage that .change has over .keypress , .focus , .blur is that .change event will fire only when input has changed [1]: http://api.jquery.com/change/

Same functionality i recently achieved using below function.

I wanted to enable SAVE button on edit.

1. Change event is NOT advisable as it will ONLY be fired if after editing, mouse is clicked somewhere else on the page before clicking SAVE button.
2. Key Press doesnt handle Backspace, Delete and Paste options.
3. Key Up handles everything including tab, Shift key.

Hence i wrote below function combining keypress, keyup (for backspace, delete) and paste event for text fields.

Hope it helps you.

function checkAnyFormFieldEdited() {
	/*
	 * If any field is edited,then only it will enable Save button
	 */
	$(':text').keypress(function(e) { // text written
		enableSaveBtn();
	});

	$(':text').keyup(function(e) {
		if (e.keyCode == 8 || e.keyCode == 46) { //backspace and delete key
			enableSaveBtn();
		} else { // rest ignore
			e.preventDefault();
		}
	});
	$(':text').bind('paste', function(e) { // text pasted
		enableSaveBtn();
	});
	
	$('select').change(function(e) { // select element changed
		enableSaveBtn();
	});
	
	$(':radio').change(function(e) { // radio changed
		enableSaveBtn();
	});
	
	$(':password').keypress(function(e) { // password written
		enableSaveBtn();
	});
	$(':password').bind('paste', function(e) { // password pasted
		enableSaveBtn();
	});
	
	
}

Use $.on() to bind your chosen event to the input, don't use the shortcuts like $.keydown() etc because as of jQuery 1.7 $.on() is the preferred method to attach event handlers (see here: http://api.jquery.com/on/ and http://api.jquery.com/bind/).

$.keydown() is just a shortcut to $.bind('keydown'), and $.bind() is what $.on() replaces (among others).

To answer your question, as far as I'm aware, unless you need to fire an event on keydown specifically, the change event should do the trick for you.

$('element').on('change', function(){
    console.log('change');
});

To respond to the below comment, the javascript change event is documented here: https://developer.mozilla.org/en-US/docs/Web/Events/change

And here is a working example of the change event working on an input element, using jQuery: http://jsfiddle.net/p1m4xh08/

You can use jQuery change() function

$('input').change(function(){
  //your codes
});

There are examples on how to use it on the API Page: http://api.jquery.com/change/